1. Field of the Invention
The present invention relates to a recording apparatus of a printing apparatus, an image forming apparatus, or the like. In particular, the invention relates to a recording apparatus capable of recording on recording materials having different thicknesses while setting a gap between recording means such as a recording head and the recording material as an appropriate value.
2. Related Background Art
Up to now, various recording materials have been proposed, on which the recording apparatus of the printing apparatus, the image forming apparatus, etc. performs recording. The above recording materials include compact recording materials with a large thickness, such as a CD-R, a DVD, and a card (hereinafter, collectively referred to as compact disc or CD). In the existing general-purpose recording apparatuses, assuming that a transport path for cut paper is adapted for recording on the recording material such as CD, the following defects are caused due to high rigidity of the CD. That is, a transport property is lowered, any scratch develops, or transport cannot be made due to problems concerning a distance between transport rollers. Accordingly, when the compact recording material with the large thickness, such as CD is transported, such an attempt that a tray is used to transport the material through a path different from the transport path for the cut paper has been made.
The tray has a larger thickness than the general cut paper. Thus, the provision of the tray requires sufficient consideration for operations of inserting the recording material into a transport roller pair, nipping it by the transport roller pair, and securing an appropriate gap between the recording head and the recording material. As a measure therefor, a method can be cited in which an operation lever is provided in the recording apparatus to release depression of a transport member in conjunction with an operation of the operation lever. According to this method, the user inserts the tray up to a predetermined position for alignment and then, the lever is operated to set the transport member in a depression state again.
FIGS. 32A, 32B, and 32C are explanatory views showing an eccentric cam 524 and a guide shaft 52 in conventional cases. Further, another attempt has been also made in which a carriage having the recording head mounted thereon is lifted through the operation of the operation lever to thereby secure the appropriate gap between the recording head and the recording material. In this case, as shown in FIG. 31, the eccentric cams 524 are provided at both ends of the guide shaft 52 for scanning the carriage and the eccentric cam operates in conjunction with the operation lever. Also, as for the positional detection of the recording material such as CD (compact disc), recording is started without any positional detection or recording is performed after the sensor mounted on the carriage directly detects a white portion position in the recording range on the CD.
However, the conventional ones devised for securing an appropriate gap between the recording head and the recording material involve the following technical problems.
(a) As shown in FIGS. 32A and 32C, the eccentric cams 524 at both ends of the guide shaft 52 are rotated to lift or lower the guide shaft vertically by the operation lever. At this time, when the print height is changed to two levels, i.e., general print height of the carriage and uppermost print height thereof, the position of the guide shaft 52 in the recording material transporting direction, that is, the position of the carriage in the recording material transporting direction is not changed. However, as shown in FIG. 32B, the print height is changed to intermediate print height, the position of the carriage in the recording material transporting direction is changed. As a result, a recording start position to the recording material should be changed for accurate recording, which leads to a complicated control.
(b) The guide shaft 52 is supported to a main body chassis through the eccentric cams 524 at both ends. Thus, parallelism of the transport roller for transporting the recording material and the guide shaft which are similarly supported to the main body chassis is lowered to some extent corresponding to an involved part tolerance in the case of supporting the guide shaft through the eccentric cams as compared with the case where the guide shaft is directly fixed to the main body chassis. Accordingly, perpendicularity between a carriage scanning direction regulated by the guide shaft and the recording material transporting direction regulated by a transport roller shaft is decreased. This may result in the deteriorated recording quality.
(c) The user operates the lever to thereby select the gap between the recording material and the recording head (gap with a sheet, hereinafter also referred to as sheet gap). As a result, any erroneous lever operation of the user makes a gap value inappropriate, which may cause such defects that the recording quality is deteriorated and the recording material contacts the recording head to stain the recording material.
(d) The position in height of the guide shaft is detected by detecting the rotation position of the eccentric cams by the sensor or the like. As a result, the costs for the sensor etc. increase.
(e) At the time of finely adjusting the general print height by an inter-sheet gap adjustment plate etc., the fine adjustment is made in a state in which the guide shaft is supported through the cams. As a result, when the cams undergo the change with time, the gap with the recording material is changed. This may result in the deteriorated recording quality, in particular, at the general print height, for which high image quality is most highly required.
(f) The structure has not been realized yet, in which the fine adjustment on the general print height is made by use of the inter-sheet gap adjustment plate. In addition, the position in height of the guide shaft is changed at three or more stages without changing the position of the guide shaft in the recording material transporting direction.